Hitherto, there is used a machine tool having front and back spindles having one and same axial line and disposed opposite each other to machine a workpiece sequentially from front and back sides while passing the workpiece between the spindles in implementing a multi-step work to one workpiece. Then, there is known a machine tool configured to suppress vibrations and deflections to machine in high precision by providing guide bushings having same axial lines respectively to the respective spindles to support a vicinity of machining position of the workpiece held by the spindles by the guide bushings (see Patent Literature 1).
There is also known a machine tool configured to suppress vibrations and deflections to machine in high precision by making a guide bushing and a tool post to be movable integrally in an axial direction (Z-axis direction) of the spindle to support a vicinity of machining position by the guide bushing while moving the tool post in the Z-axis direction (see Patent Literature 2).